You could try adding some spices like cardamom for a Middle Eastern take or cinnamon or ginger, but but the oranges and ground almonds really speak for themselves, and make for a nice grainy, moist, tangy and not overly sweet cake. You can use regular oranges, but I love blood oranges and find they have a more intense and slight more bitter flavour.
Whole orange almond cake
2 large blood oranges
1 tablespoon cointreau or grand marnier 5 eggs
1 1/4 cups (250g) caster sugar
2 1/2 cups (250g) ground almonds
1 teaspoon baking powder
Pure icing sugar, to serve
Preheat oven to 170°C. Grease and line a 20cm spring-form cake tin.
Place the two whole oranges (and cardamom pod) in a saucepan and cover with water. Bring to the boil, then reduce heat and simmer, covered, for 1 hour, ensuring that the oranges remain covered with water. Drain and cool.
When oranges are cool enough to handle, chop into quarters, discarding any seeds, then place the chunks into a blender with the Cointreau and puree until smooth. And set aside to cool thoroughly.
Beat the eggs with the sugar until thick and pale, then mix through the orange puree, ground almonds and baking powder.
Pour into prepared pan and bake for 1 hour. Leave the cake to firm up in the pan for 20 minutes then turn out, and turn over to finish cooling right way up.
To serve, sift icing sugar on top.